High-order wheel polygonal wear growth and mitigation: A parametric study

Abstract

China’s high-speed train experienced severe wheel polygonal wear during the last decade, the rail localized bending modes (RLBM) were suspected to be the major contributors behind the formation of high-order polygonal wear. To gain a deeper understanding of the polygonal wear growth and seek effective restraining measures, the influence of the crucial parameters of the vehicle/track system on the growth and mitigation of wheel polygonal wear is systematically investigated in this paper. Firstly, a simplified coupled wheelsets/track dynamic model is established for the fast polygonal wear trend analysis, and a comprehensive coupled vehicle/track dynamic model is developed for predicting the long-term polygonal wear process. Then, the formation mechanism of high-order polygonal wear is explained from the perspective of RLBM, and its evolutional progress is reproduced under the nominal parameters. Consequently, the growth law of polygonal wear is further studied under different parameters, i.e., wheelbase, wheelset mass, rail pad stiffness, rail pad damping coefficient, and fastener spacing. The results suggest that the dominant order of the polygonal wear is sensitive to the wheelbase, the polygonal wear on CRH5 Electric Multiple Units (EMUs) presents a lower characteristic frequency due to its longer wheelbase. It is also found that the EMUs operating in the extremely cold area may suffer from the slightly higher order polygonal wear owing to the stiffer rail pad. The high-order polygonal wear development can be effectively postponed by a larger rail pad damping coefficient or shorter fastener spacing.